Some prokaryotes and eukaryotes have whip-like projections that help propel the cell through liquid. What is the name of this whip-like projection?

Scientists often use cellular evidence in order to classify or group organisms. What is the best way to distinguish very simple organisms, such as bacteria, from more complex organisms, such as protists, plants, and animals?

describe the difference between prokaryotic and eukaryotic cells?

The inner membrane of the mitochondrion is folded into cristae. The cristae _______ the surface area of the inner membrane and _______ the mitochondrion's ability to produce ATP through the process of _______.

Eukaryotic cells contain organelles that harvest energy from organic compounds to make ATP. ATP is the main form of energy used by cells. Which cell organelles are responsible for making most of the cell's ATP?

Carlos is studying different types of transport in cells. He learns that water molecules commonly cross the cell membrane. Which type of transport does water use to cross the cell membrane?

_______ is the passive movement of water molecules across a cell membrane.

Osmosis involves the movement of water molecules across a cell membrane. Diffusion involves the movement of substances other than water across a cell membrane. In both of these processes, substances move from an area of high concentration to an area of low concentration. Thus, both diffusion and osmosis are forms of _______.

These layers develop into specific cells within the body through the process of _______.

Which of the following occurs during the interphase stage of the cell cycle?

Which of the following is true of the various types of cells found in an individual multicellular organism?

I. Every cell performs the same function.
II. Almost all of the cells have the same DNA.
III. Different genes are expressed in different cells.
IV. The same genes are expressed in every cell.
V. Each cell has completely different DNA.

Anna often finds that she becomes drowsy in the afternoons. The warmer her classroom is, the harder she finds it to stay awake. Why does warmth make her more tired?

When dry environmental conditions exist, guard cells reduce water loss from plants by closing the openings in their leaves. This process is an example of a feedback mechanism that plants use in order to

How are the instructions coded by DNA translated into an organism's physical traits?

AB blood type is an example of __________.

Hemophilia A is a sex-linked recessive disease. If a mother without the disease and a father without the disease have one son diagnosed with hemophilia, what is the probability that a future daughter they have together will also be afflicted with hemophilia?

Carla receives an allele for blue eyes from her mother, and an allele for brown eyes from her father.

If brown eye color is a dominant trait and blue eye color is a recessive trait, what can be determined about the color of Carla's eyes?

A cross between two squash plants that produce yellow squash results in 124 offspring: 93 produce yellow squash and 31 produce green squash. What are the likely genotypes of the plants that were crossed?

Suppose that a certain breed of cat can have black, gray, or white fur. Black fur is dominant, white fur is recessive, and gray fur is intermediate (i.e., cats with gray fur possess one allele for black fur and one for white fur).

If a gray cat and a white cat have kittens, what phenotypes could the kittens exhibit?

Cancer is a disease that usually results when

in 1996, a group of scientists from Scotland used a somatic (non-sex) cell of an adult sheep to produce an identical copy of that sheep. The process through which a genetically identical cell or organism is produced is known as _______.

What was produced as a result of the Human Genome Project?

Which of the following techniques separates molecules based on size?

Just like actual fingerprints, DNA fingerprints are unique to most individuals (other than identical twins). Today, most police departments in the United States use DNA fingerprints as a criminal investigation tool.

There are twenty standard amino acids that make up all proteins. What four elements are found in all amino acids?

A student is given a small amount of unknown tan-colored liquid substance. This unknown liquid is placed into a glass of water and mixed. Despite mixing, the tan liquid remains separated from the water and collects as a large droplet at the top. Which of the macromolecule groups is this liquid MOST likely to be a member of?

Carbohydrates, such as glucose, are excellent sources of immediate energy for living organisms. More complex carbohydrates, such as glycogen and starch, can also be used for the long term storage of energy. However, carbohydrates play other vital roles, too. Which of the following describes another common use for carbohydrates?

Which of the following is the only cell organelle that is capable of converting light energy into chemical energy?

During _________, energy from the Sun is stored in the bonds of sugar molecules.

Eukaryotic cells contain organelles that harvest energy from organic compounds to make ATP. ATP is the main form of energy used by cells. Which cell organelles are responsible for making most of the cell's ATP?

When the water availability of a plant's environment decreases, the plant can respond by closing its stomata. This reduces the amount of water that the plant loses through its leaves due to transpiration.

Closing the stomata also reduces the amount of carbon dioxide that the plant can take in through its leaves, which will most likely result in

During certain periods of the year, some species of rodents instinctively enter a state of inactivity characterized by lowered metabolism and body temperature. This state is known as _______.

Amanda is studying insects and their responses to light. She places several types of insects in a container in a dark room. She then shines a flashlight in one corner of the container. After a few minutes, she notices that all of the moths she has placed in the container are staying near the light.

Which of the following is true?

Moths show a positive response to light

think about your front porch when you turn on the lights and when you get attacked when you walk out to door!!!

Some types of organisms can increase genetic variation through reproduction. They are able to combine the genetic material of two parents, rather than copying the genetic material of a single parent. Which organisms are capable of this?

A mammal lives in an environment with warm summers and long, cold winters in which food is difficult to find. Which of the following behavioral adaptations would this mammal be the most likely to have?

Pelicans are large birds that usually live near water. They have large, expandable pouched bills, which are useful for _______.

A tick attaches to the flesh of a dog and feeds on the dog's blood for energy. This negatively impacts the dog by causing it discomfort and removing nutrients that the dog's body could have used for life processes, but it does not kill the dog.

A farmer plants two species of grass with similar nutrient needs on the same small plot of land. What kind of interaction will most likely occur between the two species?

Plants require nitrogen and phosphorous but cannot efficiently absorb these nutrients from the soil. Instead, they obtain the nutrients through fungi that live in their roots. In return, the fungi have access to carbohydrates manufactured by the plants. Without the fungi, plants would not be healthy and abundant, and the food supply of all of the organisms in the ecosystem would be in danger.

This is an example of how _________ relationships maintain balance within an ecosystem.

In which of the following ways might humans negatively impact the environment?

I. depleting the natural resources of the environment
II. destroying habitats to make room for a growing population
III. planting more trees to make up for those previously cut down

Carbon dioxide dissolves in water to form carbonic acid. This acid lowers the pH of the water and makes the water corrosive. What is likely to happen if carbon dioxide levels in the atmosphere increase?

Most modern forms of transportation are powered by fossil fuels. Carbon dioxide, methane, carbon monoxide, and other gases are released into the atmosphere during the production and combustion of these fuels. How might these gases cause climatic changes?

These gases reduce the amount of thermal energy escaping into space, effectively warming the atmosphere.

The first organisms on Earth appeared approximately 3.5 billion years ago, and all were all unicellular. Multicellular organisms have only existed for about one billion years.

What evolutionary milestone made it possible for more complex, multicellular organisms to exist?

A particular environment has enough food to support 50 rats through the winter. At the end of winter one year, there are 25 female rats and 25 male rats. Each of the 25 females gives birth to several litters of 3-6 pups each. In the fall, there are 300 rats.

Ignoring the effects of predators and disease, what will happen to this population of rats between fall and the next spring?

The fifty rats best able to get and keep food will survive to reproduce next spring.

The source of genetic variation that occurs during meiosis and results in new combinations of alleles is known as _______.

The main tenets of Darwin's theory of evolution by natural selection include:

I. Individuals can produce more offspring than can survive.
II. The traits within a population vary and are heritable.
III. Traits acquired during an individual's lifetime are heritable.
IV. Individuals compete for resources.
V. Individuals most adapted to their environments have a better chance of surviving to reproduce.

What is an example of something that resulted from a genetic variation that was favored by natural selection?

Speciation is the process by which new species

Imagine an earthquake creates a chasm that separates a population of squirrels. The two populations of squirrels evolve into two separate species. What is the name of the process by which isolated populations of the same species become new species?

The type of RNA that transfers amino acids to growing polypeptide chains during translation is known as

The instructions for building proteins necessary for all life functions are coded within an organism's genetic code. The genetic code of an organism consists of codons, or sequences of three nucleotides, that each code for a specific amino acid. Amino acids are the building blocks of proteins.

During the process, the two strands of one DNA molecule are unwound. Then, DNA polymerases add complementary nucleotides to each strand which results in the formation of two identical DNA molecules.

This process is known as DNA _______.

During transcription, enzymes bind to a molecule of DNA.
Then, the enzymes unwind and separate the DNA's double helical strands. As the molecule unwinds, complementary nucleotides pair with one of the DNA strands to form

All the information necessary for an organism to form and grow is recorded in the organism's DNA. How does DNA use its stored information to express a trait?

When mitosis occurs, the DNA inside the cell's nucleus must replicate. The new cell that is formed has an identical copy of its parent cell's DNA. That means it has the same information coded in its genes. During DNA replication, how is an accurate new copy of DNA formed?

DNA polymerases add nucleotides to the exposed base pairs according to base-pairing rules.

The main purpose of DNA is to store information. Where is information stored within a DNA molecule?

When a cell needs a particular protein synthesized, messenger RNA (mRNA) is produced from DNA through transcription. What is the maximum number of amino acids that could be coded for in the following section of mRNA: UGAUUCAGUAAC?